The body of a person who is suffering from diabetes is unable to produce an adequate amount of insulin, or the body does not react reasonably to the insulin produced by him. This fact leads to an imbalance in the glucose concentration in the blood (and thus to hyperglycemia or hypoglycemia), which can result in serious consequences, such as cetoacidosis, complications of the blood vessels, cramps or loss of consciousness. In order to maintain a healthy blood glucose level, diabetic patients normally follow strict dietary programs and link these with the giving of basal insulin and selective insulin boluses. The administration of insulin must be individually matched to the patient's body in order to supply it with the correct amount of insulin at the correct time. In order to determine the time and amount of the next insulin bolus, patients regularly measure the glucose concentration of their blood and determine the carbohydrate content of their meals.
Instead of carrying out the glucose measurements using strip-based measurement devices, as is done at three to six times by day, and in exceptional cases ten or more times per day, depending on the intensity of the therapy being carried out, it is possible to use continuously operating blood glucose measurement devices. One of the advantages of a continuously operating measurement system is the capability to calculate trend information, which can be done in a worthwhile manner only if the measurement data rate is high. The calculated trend information in this case generally relates to the previously measured values and therefore provides information about the profile of the glucose concentration in the near future. External influences such as the administering of an insulin bolus, consumption of meals or sporting activities influence the accuracy of the trend information. The accuracy of the trend calculation can be increased considerably by feeding information about these external influences to a measurement system thus, in particular, also making it possible to match the dosage of an insulin bolus more accurately to a patient's needs.
The calculated trend information relating to the measured parameter, such as a blood glucose concentration, has until now been indicated, for example, by arrows which represent the trend in the sense of it rising, falling or being constant. An upgraded display of the trend, which provides a finer graduation of the rising or falling states in the form of quickly rising, slowly rising, etc. and quickly falling, slowly falling, etc. is likewise known in the form of arrow alignments which can be distinguished from one another.
In addition to the abovementioned display of calculated trend information, it is also known for level information relating to the measured parameter to be displayed, with the measured value range of the glucose measurement device being subdivided into three or more levels. In this case, each level generally represents a physiologically relevant range, such as the hypoglycemic or hyperglycemic range, or a target value range.
The disadvantages of these known forms of display are, inter alia, that arrow information on the one hand gives only an inaccurate and incomplete picture, while more accurate measured value details are in general less useful for the patient, because of lack of specialist knowledge. Furthermore, an indication of level information likewise represents an incomplete picture because these generally represent an instantaneous record and do not provide a historical record of the measured profile of the values. In brief, the previously known forms of display provide the available information inaccurately, incompletely or else in a highly abstract form, and therefore in a form which it is very difficult for the average patient to understand. This is particularly true because the correct interpretation of the corresponding measured variables, which are associated with units such as mg/dl/min, mg/dl/h and the like, in their own right require further understanding of the processes taking place in the body.